Porter-Cable 548 Instruction Manual page 11

Now, guide the cutting along the inside of the marked area. If sharp corners are
desired cut right up to the corner of the marked edge. Stop and back up just a bit,
start the turn and cut along the side. Do the same at each corner until you end up
where you started. Then, go back and cut into each corner from the opposite
direction. The base of the machine is wide enough so you will have a solid guiding
surface on either side of the cut.
USING THE JIG SAW
First, secure the material in a bench vise or with clamps to the work table. This
is especially important when sawing small pieces or thin material. As the work
progresses in scroll or curved cut-out pieces, the material can be re-adjusted to
accommodate the movement of the saw. If the work is large enough, it may be
held only by hand across saw horses or some other rigid support. The saw cuts
freely with only light forward feed pressure on the tool. Forcing the saw will not
cause it to cut faster. Be careful not to twist the saw while making the cut. This
will cause blade breakage. To start the cut, secure the work, mark the line of cut
clearly, place forward edge of saw base on edge of the material, start motor and
when motor is up to desired speed, move blade into the work.
NOTE: Because of the variable speed feature, trial cuts at varying speeds should
be made on scrap material to determine the cutting speed for the most desirable
results.
DO NOT FORCE, LET THE SAW DO THE WORK. Move saw forward only fast
enough to keep blade cutting. If cutting becomes difficult, the blade is dull and
should be changed at once. A dull blade not only makes cutting more difficult but
also overburdens the motor. You will find the open throat and clear forward edge
of the saw base make it easy to follow the line.
LUBRICATION
Although all Porter-Cable tools have been thoroughly lubricated with a sufficient
amount of high grade lubricant at the time of manufacture, it is recommended
that the oil level in the gear chamber be checked before using your saw and
periodically thereafter as follows:
1. Remove saw blade and set machine on a level surface.
2. Remove oil plug from front of machine.
3. Gear lubricant should be level with the bottom of the oil plug hole, but should
not run out. If this condition does not exist, tip machine up and add a small
amount of Porter-Cable lubricant until it is even with the bottom of the hole.
4. NOTE: DO NOT OVERFILL. If you do, the pressure created by the pumping
action of the gears may force lubricant through seals and into motor and
mechanism chamber causing damage to the machine.
5. To change lubricant in the mechanism housing it is necessary to dismantle
the tool. This operation should only be performed by a AUTHORIZED
PORTER-CABLE SERVICE STATION or a PORTER-CABLE·DELTA
FACTORY SERVICE CENTER.
However, the lubricant may be checked as follows:
A. Remove all traces of the sawdust and grime from around the gear
housing and blade holder to eliminate the possibility of contaminating
the mechanism lubricant.
B. Remove four gear housing cover screws located around the knob on the
left side of the machine.
Disconnect the tool from the power source.
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